Receptor-interacting protein kinase 1 confers autophagic promotion of gasdermin E-mediated pyroptosis in aristolochic acid-induced acute kidney injury

Abstract

Aristolochic acid (AA) exposure is a severe public health concern worldwide. AAs damage the kidney with an inevitable acute phase that is similar to acute kidney injury (AKI). Gasdermin E (GSDME) is abundant in the kidney; thus; it-mediated pyroptosis might be essential in connecting cell death and inflammation and promoting AAs-AKI. However, the role and exact mechanism of pyroptosis in AAs-AKI have not been investigated. In this study, aristolochic acid I (AAI) was used to establish AKI models. The expression and translocation results showed GSDME-mediated pyroptosis in AAI-AKI. Knocking down GSDME attenuated AAI-induced cell death and transcription of proinflammatory cytokines. Mechanistic research inhibiting caspase (casp) 3, casp 8, and casp 9 with specific chemical antagonists demonstrated that GSDME was activated by cleaved casp 3. Furthermore, the kinase activity of upstream receptor-interacting protein kinase 1 (RIPK1) was significantly elevated, and inhibiting RIPK1 with specific inhibitors markedly improved AAI-induced cell damage. In addition, the level of autophagy was obviously increased. Pretreatment with a specific autophagic inhibitor (3-methyladenine) or knockdown of autophagic genes (Atg5 or Atg7) evidently reduced the activity of RIPK1 and downstream apoptosis and pyroptosis, thus attenuating AA-induced cell injury, which suggested that RIPK1 was a novel link conferring autophagic promotion of pyroptosis. These findings reveal GSDME-mediated pyroptosis for the first time in AAI-induced AKI, propose its novel role in the transcription of cytokines, and demonstrate that autophagy promotes pyroptosis via the RIPK1-dependent apoptotic pathway. This study promotes the understanding of the toxic effects and exact mechanisms of AAs. This will contribute to evaluating the environmental risk of AA exposure and might provide potential therapeutic targets for AA-AKI.